DESCRIPTION: In this SBIR Phase II PicoCal will develop a high throughput apparatus to measure changes in cell adhesion at the level of individual receptor-ligand interactions in real time. This tool finds critical applications in research and drug development and would allow researchers to study and manipulate adhesion by bioactive compounds to promote or inhibit physiological processes. There is a significant industrial and scientific need to detect changes that can be induced by chemokines or other highly bioactive compounds in order to elucidate the different pathways of signaling mechanisms within a cell and to screen for new key compounds interfering with such pathways. These findings may help to develop new therapies for cancer, arteriosclerosis, and autoimmune diseases, like rheumatoid arthritis. In research and drug development scientists have to study thousands of compounds to determine, if a compound activates or inhibits adhesion. In addition, many diseases such as cancer are complex and require testing multiple analytes and new key compounds for accurate drug development and treatment. There is a need for new tools in drug development to identify bio- active compounds that inhibit or promote adhesion - or modulate subtle changes in receptor affinity. The instrument can also aid researchers in studying the mechanisms of cell adhesion changes such as in tumor promotion and organ-specific metastasis. Key research and pharmaceutical applications include: leukocyte and hematopoietic stem cell adhesion to blood vessels, as well as to other cells (bone marrow niche) or to extracellular matrix (ECM) proteins, platelet adhesion, bacteria and micro-organism adhesion (bio-fouling).